Cellular and office telephones are becoming smaller from year to year, thus offering users increased convenience. One logical extension of the telephone is the wireless headset. Wireless headsets provide convenience and safety to the users of such devices as office telephones and cellular phones, by allowing the user partially or completely hands free operation of the cell phone. This is of particular importance during office work, but is also important during operation of motor vehicles, athletic activities and similar times during which users require the use of two hands for other activities. Such headsets normally comprise some sort of bead band or ear clip to retain the headset in the proper position, a microphone located near the mouth, and such wireless equipment as is necessary to communicate with a base unit located at or on the cell phone or similar device. Note that there are also “wired” headsets which do not have the advantages of wireless connection between the base unit (attached to the cellular telephone or office telephone) and the headset portion.
However, the comfort and convenience of the wireless headset may be reduced by the method of maintaining the headset in position on the user's head. Head bands which cross over the top of the head quickly become uncomfortable and may slip out of position. Ear clips also suffer from the problem of discomfort.
Wireless headsets may now be reduced in size to an ear-piece, in which the comfort and sanitation of the user and the life span of the device may in increased by providing a replaceable compliant polymer sheath for the sound tube which is inserted into the ear canal: friction between the ear canal and the sheath retains the wireless ear-piece headset in the ear canal. In alternative embodiments, the sheath and ear canal may mechanically cooperate to retain the wireless ear-piece headset in the ear canal. The sheath may be easily removed and replaced so as to adapt the length and diameter of the device for the needs and comfort of different users. Just such an invention is the subject matter of co-pending U.S. patent application Ser. No. 10/261,367 filed Sep. 30, 2002 and entitled ADJUSTABLE EAR CANAL RETENTION TRANSCEIVER/RECEIVER, to the same inventor, Shary Nassimi.
One disadvantage of such headsets is the limited space available to the designer for an antenna. One possible arrangement (seen in the previously mentioned application) is to place the antenna in the microphone tube extending from the ear in the direction of the user's mouth. Other arrangements are possible.
The present invention concerns the use of the electrical and magnetic fields of the human body to boost the gain of a wireless telephony ear-piece.
The fact that the human body has a natural electromagnetic field is well known. Such fields may extend out from the body roughly 10 to 20 centimeters depending upon direction, the ambient electromagnetic environment, the individual body and other factors. The most common situation in which the effect of the body on antennas may be seen is that of attempting to adjust the antenna of an old-fashioned television set or radio: the human achieves good reception while actually adjusting the antenna, only to see the good reception vanish when the person lets go of the antenna or moves away from it.
A number of patents cite this effect on antennas positioned close to the human body, principally in reference to devices mounted on the wrist or arm.
U.S. Pat. No. 6,373,439, issued Apr. 16, 2002 to Zurcher et al, U.S. Pat. No. 5,926,144 issued Jul. 20, 1999 to Bolanos, and U.S. Pat. No. 3,983,483 issued Sep. 28, 1976 to Pando all mention these effects in passing in regard to wrist/arm bracelets. None relate to wireless headsets of any type, much less to wireless ear-piece headsets.
Another type of discussion of these effects may be found in U.S. Pat. No. 5,659,325 issued Aug. 19, 1997 to Belcher et al for LOW IMPEDANCE LOOP ANTENNA AND DRIVE CIRCUITRY, and U.S. Pat. No. 4,368,472 issued Jan. 11, 1983 to Gandhi for MICROWAVE DOSIMETER, both of which focus on methods of actually reducing capacitive or reflective effects of radiation on or from the human body.
Of greater interest are patents on radio apparatus for use near or on the human body, in which capacitive or direct connections are used to enhance reception and/or transmission.
U.S. Pat. No. 6,047,163 issued Apr. 4, 2000 to Miyoshi for MINIATURE RADIO APPARATUS HAVING LOOP ANTENNA INCLUDING HUMAN BODY teaches a wrist watch type double contact capacitive antenna in which the user is supposed to place one part of the body in contact with one terminal of the antenna while placing a different part of the body in contact with the other electrode, thus interposing the entire body as a dielectric layer and forming a large capacitor. (See FIG. 3 and FIG. 4 of the ′163 patent). This is in contrast to applications in which a thin dielectric or no dielectric is interposed between the human body and an antenna, and thus do not use the human body as a dielectric. While the ′163 patent further mentions contact with the ear, this is in reference to an “ear-ring” design, that is, the outside of the ear, not the interior of the outer ear, nor the ear canal. Finally, there is no discussion of controlling capacitance by means of a removable sheath, since the design does not deal with the interior of the ear.
U.S. Pat. No. 5,907,522 issued May 25, 1999 to Teodoridis et al for PORTABLE DEVICE FOR RECEIVING AND/OR TRANSMITTING RADIO-TRANSMITTED MESSAGES COMPRISING AN INDUCTIVE CAPACITIVE ANTENNA teaches a bracelet or belt design for use with the torso or wrist of the user, and thus lacks many features of the present invention. It furthermore is an example of the “double antenna” type which both capacitive and inductive antennas are present as separate structures.
U.S. Pat. No. 5,678,202 issued Oct. 14, 1997 to Filimon, et al, COMBINED ANTENNA APPARATUS AND METHOD FOR RECEIVING AND TRANSMITTING RADIO FREQUENCY SIGNALS teaches a conventional telephone shape for a capacitive antenna comprising a rectangle of metal foil on the side of the handset, not a conductive plastic. The device may be held to the ear, thus establishing capacitive contact between the exterior of the ear and the antenna. However, the only reference to a “headset” in the ′202 patent is that a non-wireless headset may be plugged i held on the exterior of the ear by a strap across the head, but the capacitive contact between the body and the phone would still occur at the handset and thus NOT at the ear.
U.S. Pat. No. 5,136,303 issued Aug. 4, 1992 to Cho et al for WRIST WATCH TYPE RECEIVER teaches another wrist watch design featuring two structurally distinguishable antenna systems, two contacts, does not use conductive plastic for casing, and has numerous structural differences with the present invention.
U.S. Pat. No. 4,884,252 issued Nov. 28, 1989 to Teodoridis et al for TIMEPIECE INCLUDING AN ANTENNA teaches yet another “two antenna” wrist type system lacking numerous features of the present invention.
All of these patents lack certain features. None teach an ear-piece held in place by means of friction between the ear canal of the user and a shaft inserted therein, and none teach this method of achieving an excellent direct conduction or capacitance connection to the human body for use as an antenna. None teach that an entire case or case bottom may be made of a conductive plastic material in order to achieve the direct or capacitance connection to the human body. All teach either a handset (such as a normal telephone, even if connected to a headset) or else a wrist watch style transmitter: none teach the exclusive use of a headset type device in conjunction with the human body antenna. Finally, none teach the use of a gel layer between an ear canal shaft and the ear canal skin lining of the user in a capacitance antenna.